What is the recommended amount of omega-3 fat that we should have in a day?

In 2002, the Food and Nutrition Board of the National Academy of Science issued recommendations for dietary intakes of omega-3 fat.

New numbers are nice, but it doesn’t necessarily simplify the issue of knowing how much omega-3 fat to eat. The dietary recommendations of omega-3 fat intake are based on our needs for alpha linolenic acid (ALA) and factors that influence our ability to convert ALA to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

These are the three molecules that are denoted as omega-3 fats. EPA and DHA are found in animal foods, whereas ALA is only available from plants. All three molecules have the same bonding arrangement denoting them as an omega-3 fat, but they are not equal. ALA is essential in our diet. Humans cannot make ALA, but are able to make EPA and DHA from ALA. In our bodies, the forms of omega-3 fat that are most functional however, are EPA and DHA. Given this fact, the complexity of ALA conversion, and the listing of EPA and DHA content in food composition tables, some researchers have questioned the logic of stating these recommendations only in terms of ALA intake.

For now, infant recommendations, based on breast milk content, are for all omega-3 fats. Infants should take in 500 milligrams per day. For all other age groups, recommendations are only in terms of ALA. EPA and DHA intake is encouraged because of their protective effect against heart disease, but because they are more potent than ALA, it is impossible to issue a blanket omega-3 fat recommendation.

Based on available evidence, the only Acceptable Macronutrient Distribution Range (AMDR) set is for ALA: 0.6 to 1.2 percent of energy intake. Up to 10 percent of the AMDR can be EPA and/or DHA.

The following lists the adequate, daily ALA intake:

• Children, 1 to 3 years old, 700 milligrams.
• Children, 4 to 8 years old, 900 milligrams.
• Boys, 9 to 13 years old, 1,200 milligrams.
• Boys, 14 to 18 years old, 1,600 milligrams.
• Girls, 9 to 13 years old, 1000 milligrams.
• Girls, 14 to 18 years, 1,100 milligrams.
• Males, 19 and older, 1,600 milligrams.
• Females, 19 and older, 1,100 milligrams.
• Pregnant women, all ages, 1,400 milligrams.

Can the intake of omega-3s be too high?

The Food and Nutrition Board did not set an upper level of intake because of inadequate data and difficulties translating test tube study findings to living organisms including humans. However, the Food and Nutrition Board cautions that high intakes may impair the immune response and cause prolonged bleeding. While these side effects are rare with foods, their likelihood is greater with supplement use such as fish oil capsules and flaxseed oil.

Persons with diabetes or glucose intolerance should use omega-3 fats, especially omega-3 supplements, under the care of a medical professional because they may reduce glucose tolerance, thus causing more diabetic-like symptoms. Persons taking any medications or using herbal supplements should consult their physician to minimize the possibility of these harmful side effects.

Aren’t walnuts considered to be one of the highest sources of omega-3s?

Yes, walnuts are one of the highest sources of ALA.

In July 2003, the Food and Drug Administration approved a health claim about omega-3 fat that specifically cites walnuts as a source of omega-3 fat. Walnuts may be labeled with the following health claim: “Supportive, but not conclusive research shows that eating 1.5 ounces per day of walnuts as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease. See nutrition information for fat content.”

What other foods are naturally high in omega-3s?

Here’s a list of foods naturally high in omega-3s:

• Grain — flaxseed, flaxseed meal, oat germ, wheat germ and cereals such as Uncle Sam’s, Red River Cereal, Hodgson Mill Multigrain.
• Nuts — walnuts, butternuts, brazil nuts and pine nuts.
• Oil — canola.
• Fish — salmon, anchovies, sardines, herring, tuna, whitefish, halibut, bluefish, sweet and rainbow smelt.
• Vegetables — purslane, leeks, spinach, cauliflower, broccoli, and leafy greens.

Foods that can be modified to have more omega-3s include: eggs, milk, meat from animals fed a diet rich in omega-3s, soft or liquid margarine, and salad dressing made with some canola oil.